<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        #t_l_div{
            width: 611px;
            height: 376px;
            background-color: #e8e8e8;

            float: left;
        }

        body>div{
            /*只有把这个最大的div设置了宽度才能居中*/
            width: 1000px;
            margin: 0 auto;
        }

        #t_r_div{
            background-color: #e8e8e8;
            width: 375px;
            height: 376px;
        /*    想要使这两个独占一行的块级元素拼在同一行：左右浮动*/
            float: right;
        }

        body>div>div{
            /*避免top浮动完之后下面的顶上来（高度识别为0）的问题*/
            overflow: hidden;
            margin-bottom: 10px;
        }

        #b_l_div{
            width: 366px;
            height: 233px;
            background-color: #e8e8e8;

            float: left;
        }

        #b_r_div{
            float: right;

        }
        /*三个小div*/
        #b_r_div>div{
            width: 198px;
            height: 233px;
            background-color: #e8e8e8;
            float: left;
            margin-left: 10px;
        }







    </style>
</head>
<body>
<div>
    <div id="t_div">
        <div id="t_l_div"></div>
        <div id="t_r_div"></div>
    </div>

    <div id="b_div">
        <div id="b_l_div"></div>

        <div id="b_r_div">
            <div></div><div></div><div></div>

        </div>

    </div>
</div>
</body>
</html>